The followings are the basic terms and the Glossary which will help you to understand the basics and terms that are going to be used in the Topics and posts which knowing them will eventually help you to write guides and for posting your queries.

ACPI:
The term ACPI stands for Advanced Configuration and Power Interface. It is an open specification which is used by the Operating System to discover the hardware components and its configurations. It handles the Power Management, Thermal Management and monitoring. It provides various capabilities to the system as long as the Operating System supports the functions. The ACPI defines a set of tables in a particular system. Each table is unique and different. The table is written in ACPI Source Language (ASL) and then compiled and stored as a ACPI Machine Language (AML) format. The ACPI was firstly released in December 1996.

BIOS:
The term BIOS stands for Basic Input/Output System. Sometimes it is known as System BIOS, ROM BIOS and PC BIOS. The basic function of the BIOS is to initialize the hardware of a computer, loads the connected devices such as Keyboard, Mouse, Graphic Cards, Storage Devices and other installed hardware. The CPU accesses the BIOS before the Operating System is loaded. The BIOS performs a quick check of all the hardware connections and initializes each particular device making them ready for work. If everything is well detected without any error, the BIOS loads the Operating System into the computer's memory and finishes the boot-up process. In-case if the Operating System is not installed, the Boot Device is loaded via CD-ROM/DVD-ROM or the USB Flash Drive. The programmed software, BIOS is stored on a non-volatile memory, the ROM (Read-Only Memory) which is located on the computer or the Laptop motherboard. It acts as a bridge between the microprocessor and I/O device. The new motherboards use a new Interface of the BIOS called Unified Extensible Firmware Interface or UEFI which is a successor of the BIOS which provides some great features like GUI, Backup BIOS, Faster Booting, Multi-Boot, better security and several other features.

UEFI:
The term UEFI stands for Unified Extensible Firmware Interface is the specifications that specifies a standard software interface between the computer’s firmware and the operating system. The UEFI is a successor of BIOS. UEFI provides several features. The UEFI has replaced the legacy BIOS and it is being used on a large scale in PCs and Laptops.

Motherboard:
As the name defines, it's a main board of the computer which includes CPU, RAM, and the other peripherals such as Graphic Card/s, Storage Devices, Keyboard/Mouse and other hardware. The motherboard is sometime also referred to as Mobo in short. The Motherboard comes in different form factors (sizes). See Form Factors for more details.

Form Factor:
The term already defines its meaning. Basically, form factor means the size of the Motherboard. The form factor defines the dimensions, mounting points, rear I/O panel, peripherals such as number of PCI Devices, SATA Interference and power connectors.

SATA:
The term SATA stands for Serial ATA. It is a type of interface used to connect the storage Devices such as Hard Disk Drives (HDD), Solid State Drives (SSDs), and Solid State Hybrid Drives (SSHDs). The SATA comes in two layouts - Internal and external. The external is also referred to eSATA.

HDD:
The term HDD stands for Hard Disk Drives. It's a storage device varying with different sizes. The Hard Drive consists of a motor, the platter and the actuator. It is also known as a rotational media as the motor rotates the platter to perform the read/write function. The HDD offers a large storage capacity and is cheaper as compared to SSDs.

SSD:
The term SSD stands for Solid State Drives. As the term already define its meaning, referring to the Solid State, not in relation to the Chemistry, but the type. A Solid State drive is a storage device with non-volatile memory, NAND flash memory. The Solid State Drives consists of a board which contains several blocks of the Flash memory and the controller. The SSD has no moving components. This distinguishes them from conventional drives such as Hard Disk Drives (HDDs) or Floppy Disks Drives and this is why the SSDs provides such a great speed and is reliable. SSDs are typically more resistant to physical shock, run silently, have quicker access time and lower latency. SSDs are more expensive compared to HDDs, but can be as much as 4x faster. They come in many different form factors, such as mSATA, M.2, U.2, NVMe and PCIe Cards.

SSHD:
The term SSHD stands for Solid State Hybrid Drives. It's a traditional hard disk with a small amount of flash memory, typically 8GB or so. The purpose of these drives is to add the speed of SSDs and the cost-effective storage capacity of traditional HDDs.

mSATA:
The mSATA also called Mini SATA. The mSATA is basically an interface of SSD variant which is used in Notebooks and small computers. It is also found in some Motherboards. The mSATA was replaced by M.2.

M.2:
The M.2 is also another interface of SSD variant which can be found in Notebooks and Desktop Computers. The form factor is also known as NGFF (Next Generation Form Factor). The M.2 is a successor of mSATA which was previously used. Due to its size and speed, the M.2 Drives are being used in a large number of Notebooks and Desktop Computers.

U.2:
The U.2 is an interface of SSD used in Desktop computers. The U.2 supports four PCI Express lanes. The U.2 has several advantages over M.2.

NVMe:
NVM Express (NVMe) or Non-Volatile Memory Host Controller Interface Specification (NVMHCIS) is an interface specification for accessing non-volatile storage such as SSDs and uses PCI Express (PCIe) bus. The main benefits of NVMe-based SSDs are low latency, higher input/output operations per second (IOPS), and lower power consumption.

AHCI:
The term AHCI stands for Advanced Host Controller Interface. It is an interface specification which allows the SATA controller driver to support various advanced features such as Native Command Queuing, Hot Plug, etc. Many SATA controllers can be AHCI enabled separately or work with RAID mode.
macOS requires the SATA mode be set to AHCI.

PCIe / MiniPCIe:
PCIe stands for Peripheral Component Interconnect Express, is a type of bus used in modern PCs. PCIe is a high-speed serial bus and comes in several different revisions and variants. The PCIe interface can utilize several hardware such as graphics cards, Solid State Hard Drives, WiFi, Bluetooth, SATA Cards and USB Cards and several other devices which can be installed and used by PCIe slots. MiniPCIe is a smaller version of PCIe and is used for expansion cards in notebook computers.

RAID:
The term RAID stands for Redundant Array of Independent Disks, is a technology that combines multiple disk drives into a logical unit and serves the purposes of Data Redundancy and increased performance.
There are several RAID versions such as RAID 0, RAID 1, RAID 2, RAID 3, RAID 4, RAID 5, RAID 6 and RAID 10. RAID is commonly used on servers and high performance computers.

S.M.A.R.T.:
The term S.M.A.R.T stands for Monitoring, Analysis and Reporting Technology, often written and known as S.M.A.R.T and it is a health monitoring system which is included in Hard Drives and SSDs that detects and reports various drive reliability indicators, intended to predict the drive failures. Some of the attributes reported which includes drive temperatures, read failures, number of writes, total number of up time and the errors in the Drives. When S.M.A.R.T. data indicates a possible imminent drive failure, software running on the host system may notify the user so the required action can be taken to prevent data loss, and the failing drive can be replaced with a new one and the data integrity can be maintained.

ECC Memory:
The term ECC stands for Error-Correcting Code which is a type of RAM that can detect and correct the most common kinds of internal data corruption. It is most often used in computers where data corruption of any kind cannot be tolerated, such as for scientific or financial applications. When using macOS on a Custom Build PC or a Laptop, there can be an issue related to ECC memory. The kext " AppleTyMCEDriver.kext" causes a Kernel Panic if the user uses a System Definition (SMBIOS), that supports ECC RAM but the computer doesn't have a ECC RAM installed. In this case, “AppleTyMCEDriver.kext” must be deleted in order to boot up the particular Computer or the Laptop.

SMBIOS:
The term SMBIOS stands for System Management BIOS (SMBIOS) is a standard developed by DMTF. The standard defines the Data structures and access methods which can be used to read the information provided by the BIOS of a computer.

Kernel:
The kernel is the core of the operating system. The Kernel manages the operations of the computer and the hardware. It controls the functions of an Operating System. Kernels exist in all Linux and UNIX based systems, including macOS as well as Windows operating systems. On macOS, the kernel is located in /System/Library/Kernels, and is named as kernel.

Kext:
A kext is a kernel extension. In simple words, the Kext is a driver which enable one or more hardware devices to communicate with the computer's operating system. Without drivers, the computer would not be able to send and receive data correctly to hardware devices. If the appropriate driver is not installed, the device may not function properly. Kext files aren't individual files but a bunch of folders which contains binaries, configuration files and other resources bundled together. When using a Hackintosh, it requires a special kext to enable Audio, Ethernet, WiFi, Graphics and several other hardware. These kext serves the same purpose: To add support to hardware that isn't officially supported by Apple.

EFI System Partition (ESP):
The EFI System Partition is a special storage partition, usually on the drive on which has macOS installed. This partition holds the Bootloader, Kext, Configuration and other files which allows the macOS to boot on a PC or a Laptop. The ESP uses a FAT/FAT32 format.

FAT / FAT32:
The term FAT stands for File Allocation Table which is a computer file system architecture (originally 16-bit, now 32-bit) is the original file system format used by MS-DOS and later Windows. It can be commonly found on USB Flash Drives, SD and MicroSD cards, and other storage devices.

exFAT:
The exFAT is a file system based on the File Allocation Table architecture. The File System was introduced with Windows Embedded CE 6.0 in November 2006. exFAT is intended for use on flash drives (such as SDXC), where FAT32 is otherwise used.

MBR:
The Master Boot Record is a special type of Boot sector. The MBR holds the information on how the partitions with the File System is organized. It contains the information which identifies where an operating system is located and loads into the computer's main storage. It is used to boot legacy BIOS-based systems. MBR only supports four partition entries, and each partition is limited to a maximum of 2 TB (on disks with 512-byte sectors).

GPT:
The GUID Partition Table is a standard for the layout of the partition table on a storage device such as Hard Drives, or the Solid-State Drives. GPT supports greater partition sizes than the MBR. All modern PC operating systems support GPT including macOS and Windows, which supports booting from GPT partitions only with UEFI.

Fusion Drive:
A Fusion Drive is two separate drives combined together. It contains a Hard Drive and a Solid-State Drive. It's an example of Hybrid Drive. The benefit of this solution is that you get the best of both the Drives.

SMC:
The term SMC stands for System Management Controller. The SMC can be found in Intel-based Macintosh computers, which controls thermal and power management, battery charging, sleep/wake function, hibernation and LED indicators. It also enables the enforcement of the macOS End User License, allowing it to identify when it is running on non-Apple hardware. See also FakeSMC.

FakeSMC:
Fake SMC is an open source SMC device driver/emulator developed by netkas. FakeSMC.kext is the mandatory kext which allows macOS to boot on a non-Apple hardware. FakeSMC, along with some useful plugins, which was released with the name of "HWSensors" will emulate much of the functionalities of the SMC chip found in real Macintosh computers. See also HWSensors.

HWSensors:
HWSensors is a software bundle that includes drivers and applications that allow you to access information from hardware sensors available on your non-Apple hardware using macOS.

SIP:
The term SIP stands for System Integrity Protection. System Integrity Protection was introduced first with the Mac OS X El Capitan. It prevents potentially malicious software from modifying protected files and folders on your Mac. It also restricts the root user account and limits the actions that the root user can perform on protected parts of the Mac operating system. By default, the SIP is enabled. SIP can be partially enabled or disabled completely with the System Parameters in the Clover's config.plist file. The SIP must be disabled in order to install macOS on a Hackintosh. (This statement is not true) To disable SIP partially, two system parameters must be set in the Clover config.plist.

MAS:
The term MAS stands for Mac App Store. A place where you can download and purchase several Apps including macOS.

DSDT:
The term DSDT stands for Differentiated System Description Table is the part of ACPI standard specification. It provides the information about supported power events in a given system. ACPI tables are provided in firmware from the manufacturer of your PC or Laptop. It acts as an interface between the Operating System and the system’s hardware. To patch your DSDT, you must use a new table and then modify it according to the hardware and the function needed. The DSDT then tells your bootloader to use the new DSDT file instead of the BIOS or the default one.

SSDT:
The term SSDT stands for Secondary System Description Table is an ACPI table which is secondary to the DSDT. The SSDT is generally used to configure the power management, but it can be also be used to serve other purposes such as disabling discrete GPU on Laptops, enable USB ports etc. On some systems, multiple SSDT files may be present, named SSDT.aml, SSDT-1.aml, SSDT-2.aml, and so on.

Clover:
Clover is one of the most advanced bootloaders yet and it is capable to boot into any Operating System. The Clover bootloader is needed to boot into macOS on a PC or a Laptop. The Clover supports both UEFI and Legacy BIOS.

VGA:
The term VGA stands for Video Graphics Array. It is an analog graphics interface that uses a 15-pin D-sub connector to output the Display from the PC or Laptop.

DVI:
The term DVI stands for Digital Visual Interface is a video interface developed by the Digital Display Working Group (DDWG). There are five variants of DVI: DVI-D (digital only) Single or Dual Link; DVI-A (analog only); and DVI-I (integrated – combines digital and analog in the same connector) Single or Dual Link. You may find DVI ports on video cards in computers and as well as on high-end televisions.

HDMI:
High-Definition Multimedia Interface is a audio/video Interface for transmitting a uncompressed audio or video from the HDMI source. HDMI is a replacement for analog video standards. Nowadays, HDMI is being used by a majority of computers Display controllers, projector and Televisions.

Display Port/Mini DP:
DisplayPort (DP) is a digital display interface developed by Video Electronics Standards Association (VESA). The interface is used to transmit video from the video source. It can also carry audio, USB, and other forms of data. The interface comes in two variants. Display Port and a Mini Display port which offers a small size and flexibility. It supports a high-end resolution and is capable to transmit 4K and 5K with Audio.

Thunderbolt:
Thunderbolt is a hardware interface developed by Intel and Apple which allows to connect external peripherals to a computer. There are three variants of Thunderbolt. TB 1, 2 and 3. The Thunderbolt 1 and 2 uses the Mini Display port and the Thunderbolt 3 uses a USB Type-C. Thunderbolt 3 offers twice the bandwidth of Thunderbolt 2.

Intel HD Graphics iGPU:
It's an integrated Graphics Controller manufactured by Intel. The first Intel HD Graphics was introduced in 2010. Later on, Intel Iris Graphics and Intel Iris Pro Graphics were introduced in year 2013.

Here's a list of integrated Intel HD Graphics controllers that are supported in macOS:

Note :

This list may not be complete.

QE/CI:
Quartz Extreme and Core Image. These are two technologies that do the graphics acceleration in Mac OS X.

UHD:
Ultra High Definition. It has a resolution of 3840x2160 (16:9).

EHCI:
Enhanced Host Controller Interface. It was defined by Intel to support USB 2.0 devices.

xHCI:
eXtensible Host Controller Interface. It's a completely redesigned architecture, because it can support USB 1.0, USB 1.1, USB 2.0 and USB 3.0 devices. It is designed for upgradability, so you can use USB 3.1 or USB 4.0 devices (if they will come).

I2C:
It's a serial interface. It's used to connect low-end peripherals such as Trackpads, Touch Screens, etc. to the processor. They are very short distance and use an integrated chip to communicate between the CPU and the micro controllers.

Codec:
A codec is a device or computer program for encoding or decoding a digital data stream or signal.

HDA:
High Definition Audio. Is a specification for the audio sub-system of a personal computer. It was released by Intel in 2004 as successor to their AC'97 PC audio standard.